Developments in this type of winch include the disclosure in U.S. Pat. No. 3,728,914 wherein in order to allow the use of three ratios, one of them a direct coupling between a drive handle and the drum to give a 1:1 drive, the direct coupling is automatically disengaged when there is relative rotation between the drum and the handle when relative rotation occurs which can represent a reversal of rotation of the drive handle. Once this automatic disengagement has occurred then if the shaft is reversed once again it is not the 1:1 drive which is engaged but the third drive ratio. However, the arrangements there disclosed have the disadvantage that they only take account of the relative directions of rotation of the drum and of the handle, so that if during the time the direct drive is engaged, the drum overruns the disengagement occurs. This which quite often happens (in the operating condition known as sheet-tailing) is very undesirable.
In a prior U.S. Ser. No. 413254 now U.S. Pat. No. 3,927,580 we have shown a winch of the type described wherein however pre-selection of whether a first ratio or a third ratio is going to be engaged on a given rotation of the drive shaft is determined automatically and with reference to the absolute direction of rotation of the drive shaft; i.e., such a winch does not have its first ratio disconnected if the drum overruns.